@inproceedings{luen_nepal_frajtag_zavada_brown_hommerich_bedair_el masry_2010, title={Ferromagnetism and near infrared luminescence in neodymium and erbium doped gallium nitride via diffusion}, volume={1183}, DOI={10.1557/proc-1183-ff06-01}, abstractNote={Abstract}, booktitle={Novel materials and devices for spintronics}, author={Luen, M. O. and Nepal, N. and Frajtag, P. and Zavada, J. M. and Brown, E. and Hommerich, U. and Bedair, S. M. and El Masry, N. A.}, year={2010}, pages={45–50} }
 @article{nepal_luen_zavada_bedair_frajtag_el-masry_2009, title={Electric field control of room temperature ferromagnetism in III-N dilute magnetic semiconductor films}, volume={94}, ISSN={["1077-3118"]}, DOI={10.1063/1.3110963}, abstractNote={We report on the electrical field control of ferromagnetism (FM) at room temperature in III-N dilute magnetic semiconductor (DMS) films. A GaMnN layer was grown on top of an n-GaN substrate and found to be almost always paramagnetic. However, when grown on a p-type GaN layer, a strong saturation magnetization (Ms) was observed. This FM in GaMnN can be controlled by depletion of the holes in the GaMnN/p-GaN/n-GaN multilayer structures. We have demonstrated the dependence of the FM on the thickness of the p-GaN in this heterostructure and on the applied bias to the GaN p-n junction. The Ms was measured by an alternating gradient magnetometer (AGM) and a strong correlation between the hole concentration near the GaMnN/p-GaN interface and the magnetic properties of the DMS was observed. At room temperature an anomalous Hall effect was measured for zero bias and an ordinary Hall effect for reverse bias in a fully depleted p-GaN layer. This is in close agreement with the AGM measurement results.}, number={13}, journal={APPLIED PHYSICS LETTERS}, author={Nepal, N. and Luen, M. Oliver and Zavada, J. M. and Bedair, S. M. and Frajtag, P. and El-Masry, N. A.}, year={2009}, month={Mar} }
 @article{mahros_luen_emara_bedair_berkman_el-masry_zavada_2007, title={Magnetic and magnetotransport properties of (AlGaN/GaN): Mg/(GaMnN) heterostructures at room temperature}, volume={90}, ISSN={["0003-6951"]}, DOI={10.1063/1.2749717}, abstractNote={Dilute magnetic semiconductor films (GaMnN) are highly resistive, making transport measurements difficult to achieve. However, when GaMnN films are sandwiched between p-type doped (AlGaN∕GaN) strained-layer superlattices, holes from the superlattice interact with the Mn3+∕2+ ions and transport measurements were realized. The authors have found also that the ferromagnetic properties of GaMnN critically depend on the level of p-type doping in the superlattice. They report anomalous Hall effect measurements in this (AlGaN∕GaN):Mg∕(GaMnN) multilayered structure. The current results also demonstrate the role of carriers, especially holes, in mediating the ferromagnetic properties of GaMnN dilute magnetic semiconductor films.}, number={25}, journal={APPLIED PHYSICS LETTERS}, author={Mahros, Amr M. and Luen, M. O. and Emara, A. and Bedair, S. M. and Berkman, E. A. and El-Masry, N. A. and Zavada, J. M.}, year={2007}, month={Jun} }
 @article{reed_arkun_berkman_elmasry_zavada_luen_reed_bedair_2005, title={Effect of doping on the magnetic properties of GaMnN: Fermi level engineering}, volume={86}, ISSN={["1077-3118"]}, DOI={10.1063/1.1881786}, abstractNote={GaMnN dilute magnetic semiconductor samples, prepared by metalorganic chemical vapor deposition, are shown to exhibit ferromagnetism or even paramagnetism depending upon the type and concentration of extrinsic impurity present in the film. In addition, GaMnN deposited using growth parameters normally yielding a nonferromagnetic film becomes strongly ferromagnetic with the addition of magnesium, an acceptor dopant. Based upon these observations, it seems that ferromagnetism in this material system depends on the relative position of the Mn energy band and the Fermi level within the GaMnN band gap. Only when the Fermi level closely coincides with the Mn-energy level is ferromagnetism achieved. By actively engineering the Fermi energy to be within or near the Mn energy band, room temperature ferromagnetism is realized.}, number={10}, journal={APPLIED PHYSICS LETTERS}, author={Reed, MJ and Arkun, FE and Berkman, EA and Elmasry, NA and Zavada, J and Luen, MO and Reed, ML and Bedair, SM}, year={2005}, month={Mar} }